#### Answer

$A: 0,0 \\ B: 0,2a \\ C: 2b,2a \\ D: 2b,0$

#### Work Step by Step

An ideally placed rectangle, which we will call rectangle ABCD, should have point A placed at the origin, side AB be on the y-axis, and side AD be on the x-axis. Calling the length of AD 2b and calling the length of AB 2a, we obtain:
$A: 0,0 \\ B: 0,2a \\ C: 2b,2a \\ D: 2b,0$
Note, we call the lengths 2a and 2b because the book asks for the lengths of half of each side, so we call the length of half of AB length a and the length of half of AD b.